Organic liquid absorbent compositions based on phosphonic acid-containing polymers and di- or polyamines

ABSTRACT

Compositions useful as absorbents for organic liquids are disclosed. A diamine or polyamine is reacted with a polymeric resin that contains phosphonic acid groups to produce the absorbent compositions of the invention. Because the polymeric resin component can be combined with the amine either before or after combination with the organic liquid, the absorbents of the invention can be used in many forms. The polymeric resin component can be processed into any desired form (shaped article, solution), and the di- or polyamine can then be added to generate the absorbent in situ. Unlike spent absorbent compositions of the prior art, those of the invention can be converted to pumpable liquids by heating or by adding a gel-breaking agent to liquify the gel. A useful absorbent is recovered from the liquid by precipitation or distillation.

FIELD OF THE INVENTION

The invention relates to compositions useful as absorbents for organicliquids. The compositions, which form an insoluble gel when combinedwith an oil or an organic liquid, are the reaction products of a di- orpolyamine and a polymeric resin that contains phosphonic acid groups.

BACKGROUND OF THE INVENTION

Compositions that can absorb organic liquids, especially from aqueousmixtures, are of considerable interest. Oil-absorbent compositions aredescribed in U.S. Pat. No. 3,520,806. An alkylated styrene monomer, suchas tert-butylstyrene, is polymerized in the presence of a free-radicalinitiator and a polyethylenically unsaturated compound such asdivinylbenzene. Crosslinking from the difunctional monomer makes thecomposition insoluble in the organic liquid. When the polymercomposition and organic liquid are combined, the polymer swells withmany times its weight of the organic liquid, but remains insoluble.

Polymeric resins containing phosphonic acid groups are known in the art.Examples include styrene/1-phenylvinylphosphonic acid copolymers (Plast.Massy, No. 8 (1966) 24), crosslinked vinyl phosphonate copolymers (U.S.Pat. No. 3,726,839), and styrenic polymers that contain pendentphosphonate ester groups (J. Polym. Sci. A, Polym. Chem. Ed. 28 (1990)227; 27 (1989) 3985). The reaction products of polymeric resinscontaining phosphonic acid groups with di- or polyamines and the use ofsuch resins as absorbents for organic liquids have not been previouslydisclosed.

Previously known absorbents for organic liquids--typically thecrosslinked alkylated styrene polymers described above--have limitedutility because they are generally non-processable solids. A processablesolid, i.e., one that can be thermally processed or dissolved in asolvent, is desirable because it can be processed before use into themost effective form (e.g., fiber, particle, solid shape) for a specificend use. A liquid absorbent or a solid absorbent that can be dissolvedand used in liquid form would be preferred for some applications.

Another disadvantage of organic-liquid absorbents known in the art isthat the spent absorbent, which is typically gel-like when swollen withan organic liquid, is not easy to process or transport. In addition, theorganic liquid and absorbent polymer are not easily recovered from thespent absorbent, so the spent absorbent is typically buried orincinerated.

An ideal absorbent could be: (a) handled and used as either aprocessable solid or liquid, (b) transformed, when spent, from a gel toa pumpable, stirrable liquid, and (c) recycled to give back the organicliquid and a useful absorbent material, thus eliminating the need forcostly waste treatment and disposal.

SUMMARY OF THE INVENTION

The invention is a composition useful for absorbing organic liquids. Thecomposition comprises the reaction product of a diamine or a polyaminewith a polymeric resin that contains phosphonic acid groups. Thepolymeric resin, which is typically soluble in organic liquids, reactswith a diamine or polyamine to give a remarkably effectiveorganic-liquid absorbent.

The absorbents of the invention are versatile. Like conventionalabsorbents, those of the invention can be used as granular solids.Because the polymeric resin component can be combined with the di- orpolyamine either before or after combination with the organic liquid tobe absorbed, the absorbents of the invention can be used in many forms.

The polymeric resin component can be processed before use into the mosteffective form (e.g., fiber, particle, solid shape) for a specific enduse. The polymeric resin can be used in solution for applications wheredecanting, pumping, or spraying is desired. The di- or polyamine canthen be added to form the absorbent in situ.

Addition of the di- or polyamine to the polymeric resin/organic liquidmixture produces a gel. Unlike spent absorbents of the prior art, thoseof the invention can be transformed into pumpable, stirrable liquids byheating or by addition of a gel-breaking agent. In addition, the gel canbe broken, and the absorbent polymer can often be recovered.

DETAILED DESCRIPTION OF THE INVENTION

The compositions of the invention are the reaction products of a diamineor a polyamine and a polymeric resin that contains phosphonic acidgroups.

Diamines and polyamines useful in the invention include aliphatic,aromatic, and heterocyclic compounds containing more than one primary,secondary, or tertiary amine group. The diamine or polyamine may be, forexample, ethylene diamine, 1,4- diaminobutane, 1,6-diaminohexane,4-aminoaniline, diaminotoluenes, N,N,N',N'-tetramethylethylenediamine,1,4-diaminocyclohexane, dipyridyls, 1,4-diazabicyclo[2.2.2]octane(DABCO), and the like. Polymeric materials that contain more than oneresidual amine group are also suitable. Thus, amine-terminatedpolyethers such as "Jeffamine" polyethers (products of Texaco ChemicalCo.), amine-terminated polystyrenes, and amine-terminatedpolybutadienes, are suitable. Mixtures of amines can be used.

The amount of di- or polyamine required depends on the molecular weightand functionality of the amine used, but is typically within the rangeof about 2 to about 70 weight percent based on the total weight of theabsorbent composition. A preferred range is from about 5 to about 50weight percent.

Suitable polymeric resins are all polymeric resins that contain pendentphosphonic acid ##STR1## groups. In addition to the phosphonic acidgroups, the polymeric resin may also contain pendent phosphonate mono-or diester groups. However, polymeric resins that contain onlyphosphonate monoester and/or diester groups are not suitable.

Suitable polymeric resins include polymers of vinyl phosphonic acids andcopolymers of vinyl phosphonic acids with ethylenically unsaturatedmonomers. Suitable ethylenically unsaturated monomers include, but arenot limited to, vinyl aromatic monomers (e.g., styrene,tert-butylstyrene), conjugated dienes (isoprene, 1,3-butadiene), vinylphosphonate mono- and diesters, vinyl halides, vinylidene halides,alpha-olefins (ethylene, propylene), vinyl esters of carboxylic acids(vinyl acetate), aryl and alkyl esters of acrylic and methacrylic acid(methyl methacrylate, benzyl acrylate), acrylic and methacrylic acids,ethylenically unsaturated dicarboxylic acids (maleic acid), theiranhydrides (maleic anhydride), and their mono- and dialkyl esters(diethyl maleate), amides of ethylenically unsaturated carboxylic acids(acrylamide, methacrylamide), nitriles of ethylenically unsaturatedcarboxylic acids (acrylonitrile, methacrylonitrile), and alkyl vinylethers (methyl vinyl ether), and the like, and mixtures thereof.Polyethylene phosphonic acids, polystyrene phosphonic acids, and thelike are suitable. Also suitable are polymeric resins containingphosphonic acids such as those described by Cabasso et al. (see J.Polym. Sci. A, Polym. Chem. Ed. 28 (1990) 227; 27 (1989) 3985).

The amount of polymeric resin used in the invention depends on manyfactors, including the equivalent weights of the polymeric resin and thediamine or polyamine. Generally, the amount of polymeric resin used willbe within the range of about 30 to about 98 weight percent based on thetotal weight of the absorbent composition. A preferred range is fromabout 50 to about 95 weight percent.

Preferred polymeric resins of the invention are copolymers of a vinylphosphonic acid and a vinyl aromatic monomer. Preferably, the vinylphosphonic acid has the general structure: ##STR2## in which A is amonovalent radical selected from the group consisting of hydrogen and C₁-C₃₀ alkyl, aryl, and aralkyl. Preferably, A is phenyl.

Suitable vinyl phosphonic acids include, but are not limited to,vinylphosphonic acid, 1-phenylvinyl phosphonic acid, halogenated1-phenylvinyl phosphonic acids, 1-methylvinyl phosphonic acid,1-ethylvinyl phosphonic acid, and the like, and mixtures thereof.

The amount of vinyl phosphonic acid is not critical. It is preferred touse at least about 1% by weight based on the total weight of thepolymeric resin. A preferred amount of vinyl phosphonic acidincorporated in the copolymer is an amount within the range of about 1to about 40 weight percent based on the weight of the polymeric resin.

A vinyl aromatic monomer is preferably copolymerized with the vinylphosphonic acid. Useful vinyl aromatic monomers include all aromaticring-containing compounds that have a vinyl or α-substituted vinyl groupattached to the aromatic ring. Suitable vinyl aromatic compoundsinclude, but are not limited to, styrene, alkyl-substituted styrenes,α-methylstyrene, alkyl-substituted α-methylstyrenes, tert-butylstyrenes,nuclear methyl styrenes, halogenated styrenes, vinyl naphthalenes, andthe like, and mixtures thereof. Alkyl-substituted styrenes, such astert-butylstyrene, are preferred.

The amount of vinyl aromatic monomer used is preferably greater thanabout 60% by weight based on the weight of the polymeric resin. Aparticularly preferred range is from about 80 to about 98 weightpercent.

In one embodiment of the invention, a vinyl phosphonate mono- or diesteris copolymerized with the vinyl aromatic monomer. Some or all of thephosphonate ester groups of the resulting copolymer are then hydrolyzedto give a copolymer that contains residual phosphonic acid ##STR3##functionality. This copolymer is then combined with a di- or polyamineto give an absorbent composition of the invention.

Optionally, the compositions of the invention include a rubber. Therubber may simply be mixed or blended with the polymeric resin anddiamine or polyamine in any desired manner to produce therubber-modified composition. Often, however, the rubber cannot beblended intimately with the polymeric resin, and it is preferred tochemically graft the rubber onto the resin.

Suitable rubbers include, but are not limited to, polybutadiene,styrene-butadiene rubbers, EPDM, polyisobutylene, and the like. Anydesired amount of rubber can be used. An amount within the range ofabout 5 to about 50 weight percent based on the amount of polymericresin is preferred.

In one embodiment of the invention, a rubber is included in thecopolymerization of a vinyl phosphonic acid and a vinyl aromaticmonomer. The resulting rubber-grafted copolymer is reacted with adiamine or a polyamine to produce an absorbent composition.

The compositions of the invention are conveniently prepared by combiningthe di- or polyamine and the polymeric resin in the presence of anorganic solvent. Examples of suitable organic compounds are aliphaticand aromatic hydrocarbons (hexane, toluene, and the like), halogenatedhydrocarbons (dichloromethane, chlorobenzene, and the like), ketones,esters, ethers (tetrahydrofuran), glycol ethers, glycol ether esters,mineral oils, crude oils, and the like, and mixtures thereof. While thepolymeric resin component is soluble in the organic solvent, thereaction product of the amine and polymeric resin is an insolublecomposition that has a high affinity for the organic solvent. A gelphase quickly separates from any excess organic solvent. A usefulabsorbent composition can be isolated by separating the gel and heatingit under vacuum to remove the organic solvent used in its preparation.

The absorbents of the invention are versatile. Absorbent compositions ofthe prior art that are crosslinked during preparation, which arenon-processable, must be handled as solid particles or powders. Solidparticles are useful for some applications such as cartridge-typefilters (see, for example, U.S. Pat. No. 4,059,528), but there are manyother applications where a processable resin that can be converted insitu to an absorbent would be desirable.

The polymeric resin component can be processed into fibers, films, orshapes before reaction with the diamine or polyamine. Thus, the resincan be tailored to fit a particular absorption problem. In contrast, thecrosslinked oil-absorbent compositions known in the art usually cannotbe thermally processed into other useful forms.

Absorbents of the invention need not be prepared in advance. If desired,for example, a solution of the polymeric resin can be sprayed directlyonto an oil spill where it will be rapidly absorbed by the oil.Subsequent application of the di- or polyamine to the spill gives theabsorbent composition in situ, and turns the oil phase into a gel.

Prior-art absorbents, when spent, are not easily converted to liquids,so they cannot be transported with pumps and pipelines. The spentabsorbents are usually collected and buried or incinerated, thus wastingboth the absorbent and absorbed liquid.

In contrast, the spent compositions of the invention can be transformedeasily from the gel form back to an easily processed liquid. This isaccomplished either by heating the gel to a temperature above which thegel breaks down and forms a free-flowing liquid. Alternatively, agel-breaking agent can be added to the gel to obtain a pumpable liquid.These methods are generally not effective with the irreversiblycrosslinked absorbents commonly known in the art.

The spent absorbent compositions of the invention can be heated toconvert the gel to a liquid form. The temperature required to convertthe gel to a liquid will depend on many factors, including thecomposition and molecular weights of the diamine and polymeric resincomponents. Generally, this temperature will be within the range ofabout 60° C. to about 150° C. Once the composition is liquified, thematerial is easily pumped or stirred as desired, making pipelinetransfer feasible. Since the liquid can be stirred, distillation toseparate the organic liquid from the absorbent is also possible. Thus, acomposition may be used to clean up a spill of an organic liquid, thegel can be isolated, and the product can be converted to a liquid formfor easy transfer and disposal or separation.

Spent absorbent compositions of the invention can also be converted fromgel to liquid form by adding a gel-breaking agent. The effectiveness ofthe gel-breaking agent will depend on the structure of the absorbentcomposition and on the nature of the absorbed organic liquid. Suitablegel-breaking agents include, but are not limited to, protic acids,water, aqueous acids and bases, and aqueous salt solutions. Suitableprotic acids include mineral acids, carboxylic acids, sulfonic acids,and halogenated carboxylic and sulfonic acids. Specific examples ofsuitable protic acids include, but are not limited to, hydrochloricacid, phosphoric acid, sulfuric acid, formic acid, acetic acid,propionic acid, benzoic acid, chloroacetic acid, dichloroacetic acid,trifluoroacetic acid, methanesulfonic acid, trifluoromethanesulfonicacid, and the like, and mixtures thereof.

When nonpolar organic liquids such as toluene and hexane are absorbed inthe gel, acids such as acetic acid and hydrochloric acid can be used aseffective gel-breaking agents. Addition of the acid to the gel convertsthe gel to a liquid. The absorbent polymer can be recovered from theliquid by any suitable means, such as distillation or solventprecipitation. A convenient way to isolate the absorbent polymer fromthe gel is to acidify, then add an aliphatic alcohol such as methanol tothe liquid to precipitate the absorbent polymer. After filtration andvacuum drying, a useful absorbent is isolated. The usefulness of therecovered absorbent may depend on the relative strength of the acidused. The use of an acid having a pKa greater than about 3 allowsisolation of a polymer that retains its absorbent properties. When anacid having a pKa less than about 3 is used, a polymeric resin isobtained which must be treated with a di- or polyamine to regain theabsorbent properties. This concept is illustrated in Examples 26 and 27.

When a relatively polar organic liquid such as tetrahydrofuran isabsorbed in the gel, aqueous gel-breaking agents become effective. Evenwater may effectively break a gel that contains THF (see Example 28). Asshown in Comparative Examples 30 and 31, however, water and diluteaqueous sodium hydroxide are ineffective as gel-breaking agents whentoluene is the absorbed organic liquid.

The following examples merely illustrate the invention. Those skilled inthe art will recognize numerous variations that are within the spirit ofthe invention and scope of the claims.

EXAMPLES 1-8

Examples 1-8 illustrate the preparation of the polymeric resin componentof the compositions of the invention. A styrenic/1-phenylvinylphosphonic acid copolymer based on either styrene or tert-butylstyreneis shown (Copolymers I-VIII). The copolymers are prepared, as detailedbelow, by aqueous suspension copolymerization in the presence of aphase-transfer catalyst. Compositions and properties of the resins aresummarized in Table 1.

Preparation of Styrenic/1-Phenylvinyl phosphonic acid Copolymers(Copolymers I-VIII)

To a 12-oz. glass reaction bottle is added a styrenic monomer (100 g),tert-butyl perbenzoate (0.12 wt. % based on the amount of totalmonomer), benzoyl peroxide (0.12 wt. % based on the amount of totalmonomer), partially hydrolyzed polyacrylamide ("PAM 8173" suspendingagent, a product of Nalco, 0.50 wt. % based on the amount of totalmonomer), tetra-n-butylammonium bromide (6.0 mole percent based on theamount of 1-phenylvinyl phosphonic acid used), distilled water (100 g),and 1-phenylvinyl phosphonic acid (4.5-40 g, amount shown in Table 1).The bottle is capped and tumbled end-over-end in a bottle polymerizer at115° C. for 6 hours, then at 135° C. for another 6 hours. The beads areseparated by centrifugation, washed with water, and dried under vacuum(1 mm) at 60° C. Phosphorus content (by elemental analysis) and weightaverage molecular weight (by gel-permeation chromatography) are shown inTable 1.

                                      TABLE 1                                     __________________________________________________________________________    Styrenic/Vinyl phosphonate Copolymer Compositions                             Example                                                                            Copolymer                                                                           Styrenic                                                                             PVPA                                                                              PolyBD                                                                             Phosphorus Content                                                                          Weight Ave.                          #    #     Monomer                                                                              g   g    Calc. wt. %                                                                          Found wt. %                                                                          Mol. Wt.                             __________________________________________________________________________    1    I     styrene                                                                              5.0 --   0.8    0.7    3.9 × 10.sup.5                 2    II    styrene                                                                              6.8 --   1.0    0.6    3.3 × 10.sup.5                 3    III   styrene                                                                              9.2 --   1.4    1.2    3.0 × 10.sup.5                 4    IV    styrene                                                                              12  --   1.8    1.3    1.7 × 10.sup.5                 5    V     styrene                                                                              40  --   5.0    3.5    1.1 × 10.sup.5                 6    VI    t-butylstyrene                                                                       4.5 --   0.7    0.3    3.7 × 10.sup.5                 7    VII   t-butylstyrene                                                                       6.0 --   0.9    0.6    --                                   8    VIII  t-butylstyrene                                                                       40  --   4.5    1.4    2.5 × 10.sup.5                 9    IX    styrene                                                                              40  10   4.5    2.7    2.4 × 10.sup.5                 10   X     t-butylstyrene                                                                       40  10   4.5    1.3    2.2 × 10.sup.5                 C26  XI    styrene                                                                              **  --   1.4    1.2    0.8 × 10.sup.5                 __________________________________________________________________________     PVPA = 1phenylvinyl phosphonic acid                                           **1phenylvinyl-1-monomethylphosphonate (9.8 wt. %) used in place of PVPA      PolyBD = "Diene 35" polybutadiene rubber (product of Firestone)               Calc. wt. % Phosphorus = amount expected from 100% incorporation of           phosphonic acid monomer.                                                      Found wt. % Phosphorus = amount of phosphorus found in polymer by             elemental analysis                                                            Weight ave. mol. wt. determined by gelpermeation chromatography using         polystyrene calibration standards.                                       

EXAMPLES 9-10

Examples 9-10 illustrate the preparation of polybutadiene rubber-graftedpolymeric resins by mass-grafting copolymerization (Copolymers IX andX). Table 1 summarizes the polymeric resin compositions and properties.

Preparation of Rubber-Grafted Styrenic/1-Phenylvinyl phosphonic acidCopolymers (IX and X)

To a 12-oz. glass reaction bottle is added a styrenic monomer (100 g),tert-butyl perbenzoate (0.12 g), benzoyl peroxide (0.12 g),1-phenylvinyl phosphonic acid (40 g), and "Diene 35" polybutadiene(product of Firestone, 10 g). The bottle is capped and tumbledend-over-end in a bottle polymerizer at 115° C. for 6 hours, then at135° C. for another 6 hours. The product is dissolved in toluene, andisopropyl alcohol is added to precipitate the polymer. The product isfiltered, and dried under vacuum (1 mm) at 80° C. Phosphorus content andweight average molecular weight are shown in Table 1.

EXAMPLES 11-22

Examples 11-22 show how the polymeric resins can be combined with1,6-diaminohexane or "Jeffamine D2000" amine-terminated polyether toproduce compositions useful as organic-liquid absorbents. Absorbencyresults are summarized in Table 2. The compositions of the inventiontypically absorb many times their weight in organic solvents or crudeoil.

                                      TABLE 2                                     __________________________________________________________________________    Absorbency of Diamine-Treated Styrenic/PVPA Copolymers                        __________________________________________________________________________    Example #                                                                              11  12  13  14  15 16  17  18  19  20  21  22                        Copolymer #                                                                            I   II  III III III                                                                              IV  V   VI  VII VII IX  X                         Diamine  DAH DAH DAH DAH Jeff                                                                             DAH DAH DAH DAH DAH DAH DAH                       Wt. % diamine                                                                          15  5.0 6.7 4.4 53 10  5.0 6.0 5.0 5.0 12.5                                                                              10                        Absorbency (g/g)                                                              CH.sub.2 Cl.sub.2                                                                      24.1                                                                              32.1                                                                              24.1                                                                              32.8                                                                              16.1                                                                             34.4                                                                              8.4 --  --  --  9.6 --                        THF      16.7                                                                              20.0                                                                              13.3                                                                              15.4                                                                              10.3                                                                             20.8                                                                              6.0 13.0                                                                              10.6                                                                              6.2 6.2 7.5                       toluene  12.2                                                                              14.3                                                                              13.5                                                                              16.5                                                                              9.0                                                                              12.5                                                                              4.3 9.4 9.8 6.6 5.8 7.9                       sytrene  14.0                                                                              13.3                                                                              15.4                                                                              14.0                                                                              9.5                                                                              17.2                                                                              4.0 --  --  --  7.5 --                        cyclohexane                                                                            2.0 2.0 3.9 2.5 2.9                                                                              2.0 1.2 10.8                                                                              9.6 6.2 2.5 6.8                       hexane   --  --  --  --  -- --  --  8.6 8.8 4.6 --  5.0                       heptane  --  --  --  --  -- --  --  7.0 9.4 4.4 --  6.4                       crude oil                                                                              --  --  --  --  -- --  --  7.2 10.0                                                                              4.0 --  7.5                       __________________________________________________________________________     DAH = 1,6diaminohexane;                                                       Jeff = "Jeffamine D2000" amineterminated polyol (product of Texaco            Chemical Co.)                                                                 --: absorbency not tested                                                

Preparation of Absorbent Copolymers EXAMPLE 11

A toluene solution containing 10% by weight of copolymer I (see Table 1)is prepared. 1,6-Diaminohexane (1.5 g) is added to 100 g of the toluenesolution with stirring at room temperature. A gel forms within about 0.5h. After stirring for 1 h, the gel is spread onto an aluminum plate, isair-dried in a hood for 12 h, and is dried under vacuum (1 mm) at 80° C.for an additional 12 h. Absorbency in various organic liquids is tested,and the results appear in Table 2.

EXAMPLE 12

A toluene solution containing 10% by weight of copolymer II (seeTable 1) is prepared. 1,6-Diaminohexane (0.5 g) is added to 100 g of thetoluene solution with stirring at 50° C. A gel forms within about 0.5 h.After stirring for 1 h, the gel is spread onto an aluminum plate, isair-dried for 12 h, and is dried under vacuum (1 mm) at 100° C. for anadditional 12 h. Absorbency results appear in Table 2.

EXAMPLE 13

A solution is prepared from copolymer III (45 g) and toluene (400 g).1,6-Diaminohexane (3.0 g) is added to this solution with stirring atroom temperature. Within 5 minutes, a gel forms, and additional toluene(1000 g) is added. Filtration of the mixture through a mesh cloth gives1400 g of gel having an in situ absorbency of 30.1 g/g. The gel isspread onto an aluminum plate, air-dried for 12 h, and dried undervacuum (1 mm) at 80° C. for an additional 12 h. Absorbency resultsappear in Table 2.

EXAMPLE 14

A toluene solution containing 10% by weight of copolymer III isprepared. 1,6-Diaminohexane (0.5 g) is added with stirring at roomtemperature to 100 g of the toluene solution. A gel forms within about0.5 h. After 1 h of stirring, the gel is spread onto an aluminum plate,is air-dried for 12 h, and is dried under vacuum (1 mm) at 100° C. for12 h. Absorbency results appear in Table 2.

EXAMPLE 15

A toluene solution containing 10% by weight of copolymer III isprepared. "Jeffamine D2000" (6.0 g, product of Texaco Chemical Co.) isadded with stirring at room temperature to 100 g of the toluenesolution. A gel forms within about 30 seconds. After 1 h of stirring,the gel is spread onto an aluminum plate, air-dried for 12 h, and driedunder vacuum (1 mm) at 80° C. for 12 h. Absorbency results appear inTable 2.

EXAMPLE 16

A toluene solution containing 10% by weight of copolymer IV is prepared.1,6-Diaminohexane (1.0 g) is added with stirring at room temperature to100 g of the toluene solution. A gel forms within about 1 min. Afterstirring for about 1 h, the gel is spread onto an aluminum plate,air-dried for 12 h, and dried under vacuum (1 mm) at 80° C. for 12 h.Absorbency results appear in Table 2.

EXAMPLE 17

A toluene solution containing 10% by weight of copolymer V is prepared.1,6-Diaminohexane (0.5 g) is added with stirring at room temperature to100 g of the toluene solution. A gel forms within about 30 seconds.After stirring for about 1 h, the gel is spread onto an aluminum plate,air-dried for 12 h, and dried under vacuum (1 mm) at 80° C. for 12 h.Absorbency results appear in Table 2.

EXAMPLE 18

A toluene solution containing 10% by weight of copolymer VI is prepared.1,6-Diaminohexane (0.6 g) is added with stirring at 50° C. to 100 g ofthe toluene solution. A gel forms within about 50 min. After stirringfor about 1 h, the gel is spread onto an aluminum plate, air-dried for12 h, and dried under vacuum (1 mm) at 80° C. for 12 h. Absorbencyresults appear in Table 2.

EXAMPLE 19

A solution is prepared by dissolving copolymer VII (20 g) in cyclohexane(350 g) at 70° C. 1,6-Diaminohexane (1.0 g) is added to the cyclohexanesolution. A gel forms within about 30 min. upon cooling of the solution.Filtration through a mesh cloth followed by washing with cyclohexanegives about 320 g of gel having an in situ absorbency of 15.0 g/g. Thegel is spread onto an aluminum plate, air-dried for 12 h, and driedunder vacuum (1 mm) at 80° C. for 12 h. Absorbency results appear inTable 2.

EXAMPLE 20

A toluene solution containing 10% by weight of copolymer VIII isprepared. 1,6-Diaminohexane (0.5 g) is added with stirring at 50° C. to100 g of the toluene solution. A gel forms within about 50 min. Afterstirring for about 1 h, the gel is spread onto an aluminum plate,air-dried for 12 h, and dried under vacuum (1 mm) at 80° C. for 12 h.Absorbency results appear in Table 2.

EXAMPLE 21

A toluene solution containing 10% by weight of copolymer IX is prepared.1,6-Diaminohexane (1.25 g) is added with stirring at 50° C. to 100 g ofthe toluene solution. A gel forms within about 1 min. After stirring forabout 1 h, the gel is spread onto an aluminum plate, air-dried for 12 h,and dried under vacuum (1 mm) at 80° C. for 12 h. Absorbency resultsappear in Table 2.

EXAMPLE 22

A toluene solution containing 10% by weight of copolymer X is prepared.1,6-Diaminohexane (1.0 g) is added with stirring at 50° C. to 100 g ofthe toluene solution. A gel forms within about 2 min. After stirring forabout 1 h, the gel is spread onto an aluminum plate, air-dried for 12 h,and dried under vacuum (1 mm) at 80° C. for 12 h. Absorbency resultsappear in Table 2.

COMPARATIVE EXAMPLE 23 Preparation of1-Phenylvinyl-1-monomethylphosphonate/Styrene Copolymer (Copolymer XI)

To a 12-oz. glass reaction bottle is added1-phenylvinyl-1-dimethylphosphonate (6.5 g), sodium hydroxide (1.2 g),and deionized water (60 g). After two hours of stirring, 37%hydrochloric acid (3.0 g) is added. Partially hydrolyzed polyacrylamide("PAM 8173" suspending agent, a product of NALCO, 0.13 g) and a premixedsolution of styrene (60 g), benzoyl peroxide (0.18 g), and tert-butylperbenzoate (0.12 g) are added to the phosphonate solution. The bottleis purged with nitrogen, capped, and tumbled end-over-end in apolymerizer at 90° C. for 6 h, and at 130° C. for another 6 h. The beadsare separated by centrifugation, washed with water, and dried undervacuum (1 mm) at 80° C. Phosphorus content (by elemental analysis) andweight average molecular weight (by gel-permeation chromatography) areshown in Table 1. This polymer has pendent phosphonate groups of thestructure: ##STR4##

COMPARATIVE EXAMPLE 24 Reaction of Copolymer XI with 1,6-Hexanediamine

A 10 wt.% solution of Copolymer XI in toluene is prepared.1,6-Diaminohexane (1.5 g) is added to 100 g of the toluene solution withstirring at 50° C. No gel forms, even after 5 hours of stirring. Thisexample demonstrates the criticality of the phosphonic diacidfunctionality for forming absorbent polymers.

COMPARATIVE EXAMPLE 25 Reaction of Copolymer VII with n-Hexylamine

A 10 wt.% solution of Copolymer VII in cyclohexane is prepared.n-Hexylamine (1.0 g) is added to 100 g of the cyclohexane solution withstirring at 60° C. No gel forms, even after stirring and cooling to roomtemperature over 5 hours. This example demonstrates that the reactionproduct of a polymeric resin with a monofunctional amine is not asuitable absorbent for organic liquids.

EXAMPLES 26-29

Examples 26-29 show how useful absorbent compositions can be recoveredfrom spent absorbents by treating the spent absorbent with agel-breaking agent.

EXAMPLE 26 Recovery of Oil-Absorbent Polymer Acetic acid as Gel-breakingAgent

A portion of the absorbent copolymer prepared in Example 13 (1.0 g) andtoluene (15 g) are charged to a 4-ounce bottle. The absorbent polymerswells within 10 min. Glacial acetic acid (1.0 g) is added to the gelwith stirring. The gel immediately becomes a clear liquid. Methanol (100mL) is added in one portion. The polymer, which precipitates, isfiltered and dried under vacuum at 60° C. Yield of polymer: 0.9 g. Thepolymer is insoluble in toluene, but swells with a measured absorbencyof 14.5 g/g.

EXAMPLE 27 Recovery of Oil-Absorbent Polymer Hydrochloric acid asGel-breaking Agent Recovery of Polymeric Resin and Regeneration ofAbsorbent

A portion of the absorbent copolymer prepared in Example 13 (1.0 g) andtoluene (13.5 g) are charged to a 4-ounce bottle. The absorbent polymerswells within 10 min. Hydrochloric acid (37%) (1.0 g) is added to thegel with stirring. The gel immediately becomes a cloudy liquid. Methanol(100 mL) is added in one portion. The polymer, which precipitates, isfiltered and dried under vacuum at 60° C. Yield: 0.82 g. The polymer issoluble in toluene, and gives a clear solution. 1,6-Diaminohexane (0.2g) is added to a solution of the polymer in toluene (20 g). A gel formsimmediately. Absorbency of the gel is 17.0 g/g.

EXAMPLE 28 Recovery of Oil-Absorbent Polymer Water as Gel-breaking Agent

A portion of the absorbent copolymer prepared in Example 13 (1.0 g) andtetrahydrofuran (10 g) are charged to a 4-ounce bottle. The absorbentpolymer swells within 5 min. Distilled water (1.0 g) is added withstirring to the gel. The gel dissolves within 10 min. Precipitation withmethanol, filtration, and drying as described above results in 0.8 gpolymer. The product is insoluble in THF, but swells with an absorbencyof 10 g/g.

EXAMPLE 29 Recovery of Oil-Absorbent Polymer Aqueous Sodium Hydroxide asGel-Breaking Agent

The procedure of Example 28 is followed, except that 20% aqueous sodiumhydroxide solution is used in place of the distilled water. The geldissolves within 10 min. Isolation of the polymer in the usual way gives0.9 g polymer. The polymer is insoluble in THF, but swells with anabsorbency of 10 g/g.

COMPARATIVE EXAMPLES 30 and 31

Comparative Examples 30-31 show that the success of the gel-breakingagent will depend upon which organic liquid is present in the gel. Waterand aqueous base are capable of breaking a gel based on THF, but not onebased on toluene.

COMPARATIVE EXAMPLE 30

A portion of the absorbent copolymer prepared in Example 13 (1.0 g) andtoluene (13.5 g) are charged to a 4-ounce bottle. The absorbent polymerswells within 10 min. Distilled water (1.0 g) is added with stirring tothe gel, but the gel does not break.

COMPARATIVE EXAMPLE 31

The procedure of Comparative Example 30 is repeated, except that 20%aqueous sodium hydroxide solution is used in place of distilled water.As in Comparative Example 30, the gel does not break.

Absorbency Testing Procedure

Absorbency (grams of solvent absorbed per gram of copolymer) isdetermined as follows. The crosslinked copolymer (1.0 g) is weighed intoa 50-mL bottle. An organic liquid (50 g) is added, the bottle is capped,and the mixture is allowed to soak for 1 h (solvents) or overnight(crude oil). Free solvent or oil is decanted from the bottle, and thesample is reweighed. The weight of the gel sample minus 1 g equals theabsorbency in g solvent absorbed/g sample.

We claim:
 1. A composition useful for absorbing organic liquids, saidcomposition comprising the reaction product of a diamine or a polyaminewith a polymeric resin that contains phosphonic acid groups.
 2. Thecomposition of claim 1 wherein the di- or polyamine is selected from thegroup consisting of ethylene diamine, 1,4-diaminobutane,1,6-diaminohexane, 4-aminoaniline, diaminotoluenes,N,N,N',N'-tetramethylethylenediamine, 1,4-diaminocyclohexane,dipyridyls, 1,4-diazabicyclo[2.2.2]octane (DABCO), amine-terminatedpolyethers, amine-terminated polystyrenes, and amine-terminatedpolybutadienes.
 3. The composition of claim 1 wherein the polymericresin is selected from the group consisting of vinyl phosphonic acidpolymers, polyethylene phosphonic acids, polystyrene phosphonic acids,and copolymers of vinyl phosphonic acids with ethylenically unsaturatedmonomers.
 4. The composition of claim 1 wherein the polymeric resin is acopolymer of a vinyl aromatic monomer and a vinyl phosphonic acid of theformula: ##STR5## in which A is a monovalent radical selected from thegroup consisting of hydrogen and C₁ -C₃₀ alkyl, aryl, and aralkyl. 5.The composition of claim 1 wherein the polymeric resin is arubber-grafted vinyl aromatic/vinyl phosphonic acid copolymer.
 6. Acomposition useful for absorbing organic liquids, said compositioncomprising the reaction product of a diamine or a polyamine with apolymeric resin, wherein said polymeric resin is selected from the groupconsisting of vinyl phosphonic acid polymers, polyethylene phosphonicacids, polystyrene phosphonic acids, and copolymers of vinyl phosphonicacids with ethylenically unsaturated monomers.
 7. The composition ofclaim 6 wherein the di- or polyamine is selected from the groupconsisting of ethylene diamine, 1,4-diaminobutane, 1,6-diaminohexane,4-aminoaniline, diaminotoluenes, N,N,N',N'-tetramethylethylenediamine,1,4-diaminocyclohexane, dipyridyls, 1,4-diazabicyclo[2.2.2]octane(DABCO), amine-terminated polyethers, amine-terminated polystyrenes, andamine-terminated polybutadienes.
 8. The composition of claim 6 whereinthe vinyl phosphonic acid is 1-phenylvinyl phosphonic acid.
 9. Thecomposition of claim 6 wherein the vinyl aromatic monomer is selectedfrom the group consisting of styrene and alkyl-substituted styrenes. 10.The composition of claim 6 wherein the polymeric resin is arubber-grafted vinyl aromatic/vinyl phosphonic acid copolymer.
 11. Acomposition useful for absorbing organic liquids, said compositioncomprising the reaction product of a diamine or a polyamine with apolymeric resin, wherein said polymeric resin is a copolymer of (a) avinyl aromatic monomer selected from the group consisting of styrene andalkyl-substituted styrenes, and (b) a vinyl phosphonic acid of theformula: ##STR6## in which A is a monovalent radical selected from thegroup consisting of hydrogen and C₁ -C₃₀ alkyl, aryl, and aralkyl. 12.The composition of claim 11 wherein the di- or polyamine is selectedfrom the group consisting of ethylene diamine, 1,4-diaminobutane,1,6-diaminohexane, 4-aminoaniline, diaminotoluenes,N,N,N',N'-tetramethylethylenediamine, 1,4-diaminocyclohexane,dipyridyls, 1,4-diazabicyclo[2.2.2]octane (DABCO), amine-terminatedpolyethers, amine-terminated polystyrenes, and amine-terminatedpolybutadienes.
 13. The composition of claim 11 wherein the polymericresin is a rubber-grafted vinyl aromatic/vinyl phosphonic acidcopolymer.